Peroxydisulfate activation by LaNiO3 nanoparticles with different morphologies for the degradation of organic pollutants

A series of LaNiO3 perovskite nanoparticles with different morphologies, such as spheres, rods and cubes, were prepared through co-precipitation and hydrothermal methods, and used as the catalysts for peroxydisulfate (PDS) activation. The physical and chemical characteristics of LaNiO3 perovskites were performed, including X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen isotherm absorption (BET), electrochemical impedance spectroscopy (EIS), and X-ray photoelectron spectroscopy (XPS). The LaNiO3 with different shape showed different activities in Acid Orange 7 (AO7) degradation. Spheres-like LaNiO3 exhibited the highest catalytic activity, which is probably due to the largest specific surface area, higher proportion of reductive Ni2+ and the higher electron transfer ability. The radical scavenging experiments and electron paramagnetic resonance (EPR) revealed the production of massive sulfate radicals (SO4 center dot-) and hydroxyl radicals ((OH)-O-center dot) during the oxidation. Finally, the possible mechanisms of PDS activation and AO7 degradation were proposed. The prepared LaNiO3 perovskites also showed excellent reusability and stability.

Automated summary

A series of LaNiO3 perovskite nanoparticles with different morphologies were prepared and used as catalysts for peroxydisulfate activation. Spheres-like LaNiO3 exhibited the highest catalytic activity, likely due to its largest specific surface area, higher proportion of reductive Ni2+, and higher electron transfer ability. Radical scavenging experiments and EPR revealed the production of sulfate radicals and hydroxyl radicals during the oxidation process, and possible mechanisms of PDS activation and AO7 degradation were proposed. The prepared LaNiO3 perovskites also showed excellent reusability and stability.